覆冰四分裂导线舞动数值模拟研究

Numerical simulation on galloping of iced quad-bundled conductor

用Hamilton变分原理建立动力学平衡方程,利用罚函数法引入各子导线上间隔棒连接点之间的运动约束条件,获得覆冰四分裂导线动力方程。方程采用Newmark法进行时间积分,Newton-Raphson迭代法求解。通过数值算例验证方法的正确性。利用由风洞试验获得的覆冰四分裂导线空气动力系数,通过数值模拟获得初始攻角、风速和档距等对覆冰四分裂导线舞动的影响规律。结果表明,考虑作用于各子导线上空气动力载荷的不同对舞动幅值有明显影响;初始攻角的大小是诱发舞动的关键因素;舞动幅值随风速和档距的增大而增大。

The dynamic system equation of iced quad-bundled conductor was deduced by means of the Hamilton variational principle.The constraint conditions at the clamped points of the sub-conductors connected by a spacer were introduced by use of penalty function.The Newmark method was used in time integration and the Newton-Raphson iteration was applied to solve the nonlinear equation.The presented method was justified by means of a numerical example.The effects of attack angle,wind speed and span length on the galloping of quad-bundled conductor were numerically investigated based on the aerodynamic coefficients determined by wind tunnel experiments.It is demonstrated that the galloping amplitude is different if the difference between aerodynamic loads on each sub-conductor is taken into account;the attack angle is a key factor for the occurrence of galloping phenomenon and the galloping amplitude increases with the increase of wind speed and span length.